1. Field of the Invention
This invention relates broadly to medical devices. More particularly, this invention relates to gastric balloons.
2. State of the Art
In the treatment of obesity, gastric balloons have been inserted into the stomach to assume a portion of the volume of the stomach cavity, and reduce the available capacity of the stomach for food. This has the effect of reducing the appetite and, consequently, over time, e.g., three months, and in combination with a suitable diet, causes weight loss. However, when provided with a balloon of relatively constant volume over the treatment time, in many cases the stomach expands to accommodate the balloon (xe2x80x98balloon accommodationxe2x80x99) and recovers a portion or all of its former capacity for food intake, thereby defeating the purpose of the balloon and reducing the effectiveness of the treatment.
A number of gastric balloon systems have been invented which permit the volume of a gastric balloon to be varied over time. The purpose of the facilitating volumetric change in the gastric balloon has been to provide periods of feelings of relief and well-being to the patient, not to prevent balloon accommodation and maintain appetite reduction. One system, disclosed in U.S. Pat. No. 4,133,315 to Berman, utilizes a flexible filling/release tube permanently coupled to the balloon and which in one embodiment extends from the balloon, through the esophagus, and out the nasal pathway or mouth. In another embodiment, the tube extends surgically through the stomach wall and through the wall of the abdomen. Fluid can be pressurized into the balloon through the tube to cause balloon expansion, or released or evacuated from the tube to permit the balloon collapse, thereby varying the volume of the balloon. A similar implanted tube system is described in U.S. Pat. No. 5,234,454 to Bangs. However, for several reasons, the Berman and Bangs systems are not particularly desirable. First, the tube can cause irritation and even infection of tissue, particularly of the esophagus in the Berman system. Second, the tube can cause discomfort, at times severe, to the patient. Third, the implanted balloon tube requires that the patient be subject to a surgical incision.
In other systems, for example the system disclosed in U.S. Pat. No. 5,084,061 to Gau, a free floating gastric balloon is provided with a valve which can be detachably coupled to a filling tube. When it is desired to add or relieve pressure to the balloon, the filling tube is endoscopically extended into the stomach and coupled to the balloon. Fluid is then passed into or withdrawn from the balloon. While this system eliminates the issue of having a filling tube extend out of the body for the duration of the treatment, pressure changes to the balloon must be performed under a physician""s care and under sedation. As such, the balloon is not adaptable to change in size multiple times per day, e.g., after meals and, as such, cannot satisfactorily prevent balloon accommodation.
U.S. Pat. No. 5,259,399 to Brown discloses a system in which a balloon or bladder inserted in the stomach is controllably filled and emptied using a filling system which extends through a gastrostomy tube implanted between the stomach and the abdomen of the body and terminates outside the body. The filling system includes a reversible pump and a two-way valve connected to a filling tube. In addition, an electronic control is provided for operating the filling system and altering the size of the bladder according to a schedule or according to a set of physiological conditions of the body monitored by filling system. While this ability to vary the volume of the bladder according to a schedule or upon meeting physiological conditions is quite desirable to prevent balloon accommodation, the system has several drawbacks. First, the filling system is inserted by xe2x80x9cimplantationxe2x80x9d which requires an initial surgical procedure. In addition, extending the system through the abdomen may lead to infection. Furthermore, the external location of portions of the filling system may subject the system to unintended physical impact, resulting in physical trauma to the patient.
It is therefore an object of the invention to provide an intragastric balloon device which is adapted to be entirely located within the stomach cavity.
It is another object of the invention to provide an intragastric balloon device adapted to vary in volume without a control means which is external and mechanically connected to the balloon device.
In accord with these objects, which will be discussed in detail below, an intragastric balloon device is provided and includes a flexible bladder, a relatively rigid reservoir coupled to the bladder and adapted to hold a bladder inflation fluid, and an inflation/deflation system adapted to move or permit movement of the fluid from the reservoir and into the bladder. The intragastric balloon device is sized such that it may be inserted, in its entirety, into the stomach through the esophagus.
According to the invention, various systems may be used to move or permit movement of the fluid. In several embodiments, the system is a pump which moves the fluid between the reservoir and the bladder. In other embodiments, the system includes a mechanism for heating a fluid to cause the heated fluid to expand the bladder. According to other embodiments, no reservoir is employed and a pump pumps stomach fluid into the bladder to inflate the bladder.
According to a preferred aspect of the invention, the intragastric balloon device also includes a control system which is adapted to automatically activate the inflation/deflation system. The automatic activation may be activated by a combination of one or more of a timer, a temperature of the stomach, a pressure in the stomach, a mechanical stress in the stomach, or another sensed condition, at which the control system is programmed or otherwise configured to activate. The control system is preferably reprogrammable or instantly operable via an external transmitter. In addition, the control system and the pump, where utilized, are preferably battery-powered such that the intragastric balloon device is self-contained.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.